1. Field of the Invention
The present invention relates to a novel germicidal and fungicidal agent. More particularly, it relates to a germicidal and fungicidal agent comprising a novel quaternary ammonium salt having sufficient germicidal and fungicidal activity to replace benzalkonium chloride and a germicidal and fungicidal method utilizing it.
2. Description of the Prior Art
Quaternary ammonium salts and amphoteric surface active agents, of which benzalkonium chloride and alkyldiaminoethylglycine hydrochloride are representative examples, have widely been used because they are relatively safe and have good germicidal activity.
However, these quaternary amine salts and amphoteric surface active agents have weak fungicidal activity and corrode metallic instruments and equipments. Moreover, when anionic surface active agents are present, they form insoluble complexes with the anionic surface active agents and the germicidal activity is decreased.
Application of benzalkonium chloride as a germicidal and fungicidal agent is naturally limited by these deficiencies. When dental devices are disinfected by using benzalkonium chloride, dicyclohexylamine nitrite or sodium nitrite is generally used together with benzalkonium chloride to prevent formation of rust on the devices used. However, sodium nitrite has a problem that it has carcinogenicity through the nirosation reaction and the use of this compound is not desirable. Dicyclohexylamine nitrite has not only the same problem of carcinogenicity as sodium nitrite but also another problem that insoluble precipitate is formed in the disinfectant solution because it has limited solubility in water.
Both of the germicidal and fungicidal activity and the rust preventing property are simultaneously required not only for the germicidal and fungicidal agents for medical uses but also for other germicidal and fungicidal agents which may be in contact with the human body, such as disinfectants for environments, germicidal and fungicidal agents for fibers and germicidal and fungicidal agents for cycling cooling water.
Cooling water used with cycling for cutting machines, air conditioners and the like is in conditions suited for propagation of germs and fungi. Corrosion preventing property is required for germicidal and fungicidal agents which are added to the cooling water for prevention of the propagation of such microorganisms. The germicidal and fungicidal agents of quaternary ammonium salt type are expected to become more widely utilized if they have sufficient corrosion preventing property because they exhibit little harmful effect for the human health.
Silicone type quaternary ammonium salts have been known as germicidal and fungicidal agents for fibers. This type of germicidal and fungicidal agents is generally applied for fiber treatment in combination with reactive silicone resins. Fiber products treated with the combined agents have problems, such as discoloration, decrease of fluorescent whiteness, decrease of water absorption, decomposition of the quaternary ammonium salt by heating, decrease of the germicidal activity by the decomposition, formation of rust in machines used for the treatment and the like other problems. It is inevitable that applications of the germicidal and fungicidal agents of this type are limited because of these problems.
Quaternary ammonium salts having the following formula have been proposed as the germicidal and fungicidal agents by the present inventors (Japanese Patent Publication Heisei 1-33589 and Heisei 3-35282): ##STR1## wherein R.sup.8 is an alkyl group or alkenyl group having 8 to 22 carbon atoms, R.sup.9 and Rio are an alkyl group having 1 to 5 carbon atoms, respectively, R' is an alkylene group having 2 to 4 carbon atoms, m is an integer of 1 or 2, n is an integer in the range from 1 to 5 and Y.sup.m- is an ion of an alkyl ester of phosphoric acid or an ion of a polyoxyethylenealkylether ester of phosphoric acid.
The germicidal and fungicidal agents proposed above have a problem that they do not have sufficient activity against Gram-negative bacteria even though they have sufficient activity against Gram-positive bacteria.